pub const CMD_BIND: u8 = 0x20;
pub const CMD_RESET: u8 = 0x21;
pub const CMD_ACCEPT: u8 = 0x22;
pub const CMD_PING: u8 = 0x10;
pub const CMD_CREATE: u8 = 0x30;
pub const CMD_CONNECT: u8 = 0x40;
pub const CMD_FORWARD: u8 = 0x41;
pub const CMD_ERROR: u8 = 0x50;